Pump for medical purposes



March 10, 1910 SQ LA ERDAL 3, 9

I PUMP on mnnxcn, PURPOSES 2 Sheets-Sheet 1 FiledFeb. 15, 1968 il it'lllllll. llllllllllllllLnnnclJ FIG.1

, mvemron: Asmund-s. Laerclu United States Patent Office Patented Mar.10, 1970 3,499,601 PUMP FOR MEDICAL PURPOSES Asmund S. Laerdal,Stavanger, Norway Filed Feb. 15, 1968, Ser. No. 705,746 Claims priority,application Norway, Feb. 18, 1967, 166,906/ 67 Int. Cl. F04!) 37/10,21/04 US. Cl. 230-492 7 Claims ABSTRACT OF THE DISCLOSURE The inventionrelates to a double-acting, combined vacuum and pressure pump formedical purposes. Such pumps may be used for the removal of secretionand for use in combination with asthma appliances.

Known pumps of this type have the disadvantage that relatively smallsecretion particles which unavoidably penetrate into the pump chambermay give rise to difliculties. A further disadvantage consists in thatspecial tools are necessary for their assembly and disassembly and thatthis work can only be done by mechanical experts. Furthermore, it mayfrequently be necessary to clean the pump. This cleaning must as a rulebe carried out by people having little mechanical knowledge, such asnurses.

According to the present invention, there is provided a double actingcombined vacuum and compression pump, for medical purposes, such pumpcomprising a pump cylinder having two pistons axially slidable therein,such pistons being spaced apart by a rigid connecting member to form afree space between said pistons, an external conduit connected to eachof the cylinder end walls, a crank mounted for rotation in the cylinderside wall about an axis substantially perpendicular to the cylinderaxis, said crank engaging said connecting member to reciprocate saidconnecting member and pistons upon rotation of said crank, the side wallof the cylinder having an aperture therethrough in communication withsaid free space, said pistons each having an orifice providingcommunication between the cylinder end chambers and the free space, afirst pair of valves associated with the cylinder end walls, selectivelyto disconnect said external conduit from said cylinder end chambers, anda second pair of valves associated with said piston orifices, wherebyreciprocation of said pistons causes said cylinder end chambers to actas suction chambers, and said free space to act as a compressionchamber.

The pump according to the invention, which is suitable for use both forthe removal of secretion and also in combination with asthma appliances,is, due to the provision of the valves, substantially insensitive to thepenetration of secretion particles into the pump interior. The pumpcontinues to operate even if a relatively large quantity of secretionhas penetrated into the pump interior. The secretion which has enteredtherein is able to penetrate through the valves into the free space andto flow from there, via the aperture in the cylinder wall, without thepump coming to a standstill. Simultaneously, the simple association ofthe pump and pump drive crank ensures that the unit can, for cleaningpurposes, be assembled and reassembled without difficulty.

According to a preferred embodiment, the two pistons are connectedtogether by a wide web extending between said pistons and formed with atransverse slot engaged by said crank. Advantageously, a seating flangeextends outwardly from the central portion of said cylinder side wall,and an electric motor, having an annular rim thereon, seats in anannular groove on said seating flange, the drive shaft of said motorbeing connected to said crank.

In order that the invention may more readily be understood, thefollowing description is given, merely by way of example, referencebeing made to the accompanying drawings, in which:

FIGURE 1 is a longitudinal section through one embodiment of the pumpaccording to the invention and through a secretion container connectedthereto, and

FIGURE 2 shows a cross-section through the pump cylinder of FIGURE 1,half-way up the height thereof.

The pump has a single cylinder 1 which is manufactured from transparentplastics material. Enclosed in the cylinder are two plungers or pistons2 connected together co-axially, by a broad plate-like web 3 centrallyrecessed at both ends and forming between the pistons a free space 2'.In the web 3 is a slot 4 which extends transversely of the cylinder axisand in which a crank shaft arm 5 engages. The crank shaft arm 5 has asurrounding self-lubricating sleeve 20 and is directly conne'cted withthe driving shaft of an electric motor 15 arranged on the cylinder wall.

The motor may receive its current from electrical batteries or directlyfrom the mains, or from the mains via a rectifier.

Arranged in the plungers 2 and in the covers of the cylinder 1 arevalves 11 designed as large, soft clack valves. The valves 11 of theplungers are situated in the recessed portions of the web. The clackvalves readily permit the passage of secretion particles, without thepump being thereby put out of operation. During the operation of theplungers, the free space 2' serves as a compression chamber whereas avacuum forms in the cylinder end chambers 17. In the illustratedembodiment, the vacuum chambers 17 are connected by flexible tubes 8 and9 with a separate secretion collector container 7, which may beconnected by means of a pipe 10, with the patient. .Alternatively, thevacuum chambers 17 may be connected, by means of the flexible tubes 8and 9 directly With the patient, the container 7. then being omitted.

Formed in the zone of the free space 2' in the lateral wall of thecylinder 1 is an aperture 6, which serves for the discharge of anysecretion which has penetrated into the cylinder. The aperture 6 may, ifdesired, be provided with a flexible tube, for the purpose of blowing-inair when treating an asthma patient.

The pump operates with only a slight degree of resistance and isself-lubricating. This is extremely important for medical pumps since,when the pump according to the invention is used in combination withasthma appliances, it is necessary to avoid contamination of thecompressed air by oil vapours, and it is also necessary to avoidexcessive heating of the air. The large-dimensioned clack valves 11 arepreferably manufactured fromsoft silicone rubber, so that theirfunctioning is not detrimentally influenced by secretion particles, anda good sealing effect is always achieved. Filters 12 are fitted in bothends of the cylinder. v

The central zone of the side wall of the cylinder 1 is provided with aseating flange 16, having an annular groove therein, in which a flangeon the base 13 of the motor 15 seats. The flange on the base 13 is heldin place by countersunk head screw bolts 14, which ensure accuraterelative positioning of the motor and the cylinder. A packing isadditionally provided on the inner side of the motor base 13. By meansof the motor base 13 and the packing, the cylinder chamber is sealedwith respect to the motor 15.

Since the cylinder housing 1 and the plungers 2 are manufactured from atransparent plastics material, effective monitoring of the pump isguaranteed, so that the necessity for cleaning is observed in good time.The transparency furthermore facilitates the assembly of the crank shaftarm 5.

The pump is mounted, preferably upright, in a suitcase. In use, however,it may also be horizontal, so that the pump cylinder adopts a horizontalposition. The aperture 6 for discharge of the secretion for the centralcompression chamber is therefore formed in the cylinder Walls, on thedownwardly located side, so that the secretion is able, during operationof the pump in the horizontal postion, to run unhindered out of thecompression chamher.

What is claimed is:

1. A double acting combined vacuum and compression pump, for medicalpurposes, said pump comprising, in

combination:

(a) a pump cylinder;

(1)) at least one side wall and two end walls to said cylinder, at leasta part of said side wall being transparent;

(c) two spaced coaxial pistons axially slidable in said cylinder;

(d) a web rigidly connecting said pistons to define a free spacetherebetween, said web being centrally recessed at both ends andprovided with a slot extending transversely of the cylinder axis;

(e) crank means mounted in said cylinder side wall for rotation about anaxis perpendicular to the cylinder axis, said crank means engaging insaid slot of said web, effective to reciprocate said web and pistonsupon rotation of said crank means;

(f) an external conduit connected to each of said cylinder end walls;

(g) an aperture through said cylinder side wall communicating with saidfree space;

(h) an orifice situated centrally in each piston providing communicationbetween cylinder interior adjacent said end walls and said free space;

(i) a first pair of centrally positioned, large dimension, soft clackvalves associated with said cylinder end walls selectively to disconnectsaid conduit; and

(j) a second pair of centrally positioned, large dimension, soft clackvalves associated with said piston orifices, whereby reciprocation ofsaid pistons causes said cylinder interior adjacent said end walls toact as suction chambers and said free space to act as a compressionchamber.

2. A pump as defined in claim 1, and further comprising a separatecontainer connected to said external conduit, and separate conduit meansfor connecting the container to a source of secretions, wherebysecretions are collected in the container during pump operation.

3. A pump as defined in claim 1, and further comprising a seating flangeextending outwardly from said cylinder side wall, an annular groove insaid seating flange, an electric motor, an annular rim on said motorseating in said annular groove, countersunk head screw bolts connectingsaid annular rim to said seating flange, and a drive shaft to said motordriving said crank means, said countersunk head screw bolts ensuringaccurate relative positioning of said motor and said cylinder.

4. A pump as defined in claim 1, wherein said cylinder side Walls aremanufactured from a transparent plastics material.

5. A pump as defined in claim 4, wherein said pistons are manufacturedfrom a transparent plastics material.

6. A pump as defined in claim 1, in which said pump is self-lubricating.

7. A pump as defined in claim 6, in which said crank means comprises acrank arm having a surrounding selflubricating sleeve.

References Cited UNITED STATES PATENTS Re. 24,932 1/1961 Davey.

84,754 12/1868 Palmer 103-186 275,680 4/1883 Marchand 103-186 1,952,6403/1934 Ventress et a1. 103-186 2,515,956 7/1950 Greenberg. 2,295,5929/1942 McConnohie 103-186 2,611,323 9/1952 Digney. 2,704,234 3/1955 Loveet a1 308-237 3,120,338 2/1964 Rhodes 230-58 3,410,477 11/1968 Hartley230- 95,943 10/ 1869 Sluthoin 103-186 FOREIGN PATENTS 417,127 1910France.

HENRY F. RADUAZO, Primary Examiner

